A well-preserved ‘placoderm’ (stem-group Gnathostomata) upper jaw from the Early Devonian of Mongolia clarifies jaw evolution [PDF]
Royal Society Open Science, 2023 The origin of jaws and teeth remains contentious in vertebrate evolution. ‘Placoderms’ (Silurian-Devonian armoured jawed fishes) are central to debates on the origins of these anatomical structures.
Martin D. Brazeau +7 more
doaj +4 more sources
New information on Brindabellaspis stensioi Young, 1980, highlights morphological disparity in Early Devonian placoderms [PDF]
Royal Society Open Science, 2018 Acid-prepared specimens of the placoderm Brindabellaspis stensioi (Early Devonian of New South Wales, Australia) revealed placoderm endocranial anatomy in unprecedented detail.
John A. Long +2 more
exaly +3 more sources
Extreme lower jaw elongation in a placoderm reflects high disparity and modularity in early vertebrate evolution [PDF]
Royal Society Open ScienceJaws are a key vertebrate feature that arose early in our evolution. Placoderms are among the first jawed vertebrates; their fossils yield essential knowledge about the early diversification of gnathostome feeding strategies, diets and modularity ...
Melina Jobbins +6 more
doaj +4 more sources
Was the Devonian placoderm Titanichthys a suspension feeder? [PDF]
Royal Society Open Science, 2020 Large nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial ...
Samuel J. Coatham +3 more
doaj +8 more sources
Squamation and scale morphology at the root of jawed vertebrates [PDF]
eLife, 2022 Placoderms, as the earliest branching jawed vertebrates, are crucial to understanding how the characters of crown gnathostomes comprising Chondrichthyes and Osteichthyes evolved from their stem relatives.
Yajing Wang, Min Zhu
doaj +2 more sources
A Bayesian approach to dynamic homology of morphological characters and the ancestral phenotype of jawed vertebrates [PDF]
eLife, 2020 Phylogenetic analysis of morphological data proceeds from a fixed set of primary homology statements, the character-by-taxon matrix. However, there are cases where multiple conflicting homology statements can be justified from comparative anatomy.
Benedict King, Martin Rücklin
doaj +2 more sources
Hard-object feeding adaptations infer relative predator-prey size relationships in Devonian placoderms [PDF]
Scientific ReportsDevonian placoderms exhibit exceptional diversity in jaw and dental morphology, making them an ideal system for examining early gnathostome feeding mechanisms.
D. Rex Mitchell +5 more
doaj +2 more sources
Biomechanical analyses of pterygotid sea scorpion chelicerae uncover predatory specialisation within eurypterids [PDF]
PeerJ, 2022 Eurypterids (sea scorpions) are extinct aquatic chelicerates. Within this group, members of Pterygotidae represent some of the largest known marine arthropods.
Russell D. C. Bicknell +5 more
doaj +3 more sources
Pelvic and reproductive structures in placoderms (stem gnathostomes)
Biological Reviews, 2014 Newly discovered pelvic and reproductive structures within placoderms, representing some of the most crownward members of the gnathostome stem group and the most basal jawed vertebrates, challenge established ideas on the origin of the pelvic girdle and ...
Kate Trinajstic (698282) +4 more
core +7 more sources
Re-make, re-model: evolution and development of vertebrate cranial lateral lines. [PDF]
Biol Rev Camb Philos SocABSTRACT Lateral lines are placodally derived mechanosensory systems on the heads and trunks of many aquatic vertebrates. There is evidence of lateral lines in the earliest known vertebrate fossils, and they exist in organisms with widely different craniofacial morphologies – including the presence or absence of jaws, external or internal nostrils, and
Venkataraman V +3 more
europepmc +2 more sources